Develop Reference

c# How to Intercept "Save Print Output As" dialog in Revit

I am trying to intercept the "Save Print Output As" dialog in Revit so I can programmatically insert a path and file name. This dialog pops up every time for every view or sheet that is printed when printed separately or only once if a combined document is printed once.
So far, I have assembled the viewset however when it comes time to print, I do not have access to the window because it opens and closes too soon. I am hoping there is a more "hacky" way to intercept it.
In Revit, the event handler:
a.ControlledApplication.DocumentPrinting += new EventHandler<Autodesk.Revit.DB.Events.DocumentPrintingEventArgs>(AppDocumentPrinting);
only activates after the name/destination has been selected but before the document has printed so it doesnt quite help.
I have found this post which explains how to cycle through the windows which I am able to do but I don't know how to listen for the window to be opened and I can't find anything on it. The SO post also mentions something about p/invoke but I haven't found much documentation on it.
I have looked at subscribing to events but I haven't found anything on being able to subscribe to listen to a window opening.
My printer setup is currently Microsoft print to pdf which doesn't seem to allow the PrintToFile option. Regardless though, I would still like to be able to handle the dialog if it pops up if it is possible.
Any and all help/direction is appreciated.
My code:
EnumWindows(new EnumWindowsProc(EnumTheWindows), IntPtr.Zero); // cant find window because it doesnt exist
printManager.SubmitPrint(); // Window opens for user input here and then closes
// doc.Print(pdfviewSet); // option B: Window opens for user input here and then closes
EnumWindows(new EnumWindowsProc(EnumTheWindows), IntPtr.Zero); // cant find window because it doesnt exist
code adapted from other SO post
// P/Invoke declarations <--- suspect the answer might lie here?
protected delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Unicode)]
protected static extern int GetWindowText(IntPtr hWnd, StringBuilder strText, int maxCount);
[DllImport("user32.dll", CharSet = CharSet.Unicode)]
protected static extern int GetWindowTextLength(IntPtr hWnd);
[DllImport("user32.dll")]
protected static extern bool EnumWindows(EnumWindowsProc enumProc, IntPtr lParam);
[DllImport("user32.dll")]
protected static extern bool IsWindowVisible(IntPtr hWnd);
[DllImport("user32.dll", SetLastError = true)]
static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint processId);
// Callback for examining the window
protected static bool EnumTheWindows(IntPtr hWnd, IntPtr lParam)
{
int size = GetWindowTextLength(hWnd);
if (size++ > 0 && IsWindowVisible(hWnd))
{
StringBuilder sb = new StringBuilder(size);
GetWindowText(hWnd, sb, size);
if (sb.ToString().Equals("Save Print Output As", StringComparison.Ordinal))
{
uint procId = 0;
GetWindowThreadProcessId(hWnd, out procId);
Debug.WriteLine($"Found it! ProcID: {procId}");
FlaUI.Core.Application application = FlaUI.Core.Application.Attach(Process.GetCurrentProcess());
string appName = application.Name;
Window mainWindow = application.GetMainWindow(new UIA3Automation());
ConditionFactory cf = new ConditionFactory(new UIA3PropertyLibrary());
mainWindow.FindFirstDescendant(cf.ByProcessId(int.Parse(procId.ToString()))).AsTextBox().Enter("test"); // try to enter info here but returns null because window has closed.
}
}
return true;
}
Dialog I am trying to intercept:
Other info I have looked at:
p/invoke - not too sure how to implement this.
tried this but printed a blank page
How to subscribe to events
Tim Corry's Youtube video on subscribing to events

C# Windows Mobile 6.5.3 extend Winform MainMenu

what I want to do is to extend the MainMenu of the Windows Mobile Winforms to have a second menu level. If you tip short on the menu button it will do the event action but if you press it longer a second menu level should pop up. The MainMenu is very deficient in its managed functions so I had to find another way. I archived this by deriving MainMenu and add some SubClassing.
public delegate IntPtr Win32WndProc(IntPtr hWnd, int msg, int wParam, int lParam);
[DllImport("coredll.dll", EntryPoint = "FindWindow", SetLastError = true)]
public static extern IntPtr FindWindow(string lpClassName, IntPtr lpWindowName);
[DllImport("coredll.dll")]
public static extern bool EnableWindow(IntPtr hWnd, bool bEnable);
[DllImport("coredll")]
public static extern IntPtr SetWindowLong(IntPtr hWnd, int nIndex, Win32WndProc newProc);
int GWL_WNDPROC = (-4);
int GW_CHILD = 5;
IntPtr _oldToolbarProc;
IntPtr _oldMenuWorkerProc
void Hookup()
{
//find the window to hook
var hWndHooked = FindWindow("HHTaskbar", IntPtr.Zero);
if (hWndHooked == IntPtr.Zero)
return;
//enable the taskbar, not realy necessary
EnableWindow(hWndHooked, true);
//find the menu_worker window
var menuWorkerWnd = FindWindow("menu_worker", IntPtr.Zero);
if (menuWorkerWnd == IntPtr.Zero)
return;
var toolbarWnd = GetWindow(menuWorkerWnd, GW_CHILD);
if (toolbarWnd == IntPtr.Zero)
return;
Win32WndProc newMenuWorker = MenuWorkerProc;
_oldMenuWorkerProc = SetWindowLong(menuWorkerWnd, GWL_WNDPROC, newMenuWorker);
Win32WndProc newToolbar = ToolbarProc;
_oldToolbarProc = SetWindowLong(newToolbarWnd, GWL_WNDPROC, newToolbar);
}
The toolbar subclassing measures the time between WM_LBUTTONDOWN and WM_LBUTTONUP
and depending on the time leaped between these events a context Menu is invoked.
If the context menu is invoked the menu_worker subclassing must suppress the WM_COMMAND of the pressed button.
This works fine for a single window. But if I use it on a second form they will recongize both the same toolbar and menuworker and application crashes.
What I tried is to hook and unhook in the onFocus /onLostFocus events of the parent form.
But sadly onFocus is called before the right window is visible and it also gets the wrong window handle :(
What I did now (I know a very bad hack) is to start a time in the onFocus event and wait for 1000ms and hook it up then. This results in a 50:50 change to hook the right window..
Isn't there a better solution for subclassing the right window?

Send keystroke to application in c# (sendkeys, postmessage, sendmessage all not working)

I am trying to do one of the following
1. open desired program and press a key programmatically
2. find open window of program and press a key programmatically
(either is fine)
I have tried numerous implementations of SendKeys.SendWait(), PostMessage(), and SendMessage() unsuccessfully. Below are my code snippets
//included all these for attempts
[DllImport("User32.dll")]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("User32.dll")]
static extern int SetForegroundWindow(IntPtr hWnd);
[DllImport("User32.Dll", EntryPoint = "PostMessageA")]
static extern bool PostMessage(IntPtr hWnd, uint msg, int wParam, int lParam);
[DllImport("user32.dll")]
static extern byte VkKeyScan(char ch);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
Get handle of window, variables used by sendmessage/postmessage/sendkeys
IntPtr ptrOBS = proc.Handle;//this works properly, proc is instantiated properly
//IntPtr ptrOBS = FindWindow(null, "Open Broadcaster Software v0.472b");
SetForegroundWindow(ptrOBS);
const UInt32 WM_CHAR = 0x0102;
const uint WM_KEYDOWN = 0x100;
const int VK_R = 0x52; // taken from http://msdn.microsoft.com/en-us/library/dd375731(v=vs.85).aspx
const int VK_S = 0x53;
SendMessage attempt:
SendMessage(ptrOBS, WM_KEYDOWN, (IntPtr)VK_R, (IntPtr)1);//tried both WM_CHAR and WM_KEYDOWN
PostMessage attempt:
string message = "rs";
bool sent = PostMessage(ptrOBS, WM_KEYDOWN, VkKeyScan(message[0]), 0);
SendKeys attempt:
SendKeys.SendWait("{r}");
Tried SetFocus on the parent window (application) and child window (button triggered by keypress im trying to send):
static void SetFocus(IntPtr hwndTarget, string childClassName)
{
// hwndTarget is the other app's main window
// ...
IntPtr targetThreadID = GetWindowThreadProcessId(hwndTarget, IntPtr.Zero); //target thread id
IntPtr myThreadID = GetCurrentThread(); // calling thread id, our thread id
try
{
bool lRet = AttachThreadInput(myThreadID, targetThreadID, -1); // attach current thread id to target window
// if it's not already in the foreground...
lRet = BringWindowToTop(hwndTarget);
SetForegroundWindow(hwndTarget);
// if you know the child win class name do something like this (enumerate windows using Win API again)...
IntPtr hwndChild = (IntPtr)1183492;//(IntPtr)EnumAllWindows(hwndTarget, childClassName).FirstOrDefault();
if (hwndChild == IntPtr.Zero)
{
// or use keyboard etc. to focus, i.e. send keys/input...
// SendInput (...);
return;
}
// you can use also the edit control's hwnd or some child window (of target) here
SetFocus(hwndChild); // hwndTarget);
SendKeys.SendWait("{r}");
}
finally
{
SendKeys.SendWait("{r}");
bool lRet = AttachThreadInput(myThreadID, targetThreadID, 0); //detach from foreground window
SendKeys.SendWait("{r}");
}
}
For NSGaga:
string windowName = "Open Broadcaster Software v0.472b";
IntPtr outerPtr = FindWindow(null, windowName);
IntPtr ptrOBS = (IntPtr)527814;//button that im trying to trigger keypress on
SetForegroundWindow(outerPtr);
SetForegroundWindow(ptrOBS);
SetFocus(outerPtr, "OBSWindowClass");//SetFocus(ptrOBS, "Button");
const UInt32 WM_CHAR = 0x0102;
const int VK_R = 0x52; // taken from http://msdn.microsoft.com/en-us/library/dd375731(v=vs.85).aspx
const int VK_S = 0x53;
//SetForegroundWindow(ptrOBS);
System.Threading.Thread.Sleep(3000);
SendKeys.SendWait("{r}");
SendMessage(outerPtr, WM_KEYDOWN, (IntPtr)VK_R, (IntPtr)1);
PostMessage(outerPtr, WM_KEYDOWN, VkKeyScan('r'), 0);

You cannot reliably use SendMessage and PostMessage for synthesizing keyboard input. They are just not designed for this. These messages (WM_CHAR, WM_KEYDOWN, etc.) are notifications raised by lower-level subsystems when keyboard input has been received, processed, and forwarded on to the appropriate recipient. Sending or posting these messages yourself is like prank-calling someone.
SendKeys (like all other input synthesizer methods, including the SendInput function which was explicitly designed for synthesizing keyboard input and in at least some implementation is what SendKeys actually uses under the hood) works only when the window you wish to receive the keyboard input has the focus. In Windows, only focused (active) windows receive input events.
So SendKeys is probably the way to go if you're ever going to get this to work (either that or P/Invoking SendInput and all of its associated structures), but you do need to respect the caveat that the recipient window must have the focus. Otherwise, it's not going to get anything.
It looks like from your sample code that you're trying to use the SetForegroundWindow function to meet this precondition. Unfortunately, you're passing it an invalid value, and not doing any error checking that might alert you to this mistake. Specifically, this code is wrong:
IntPtr ptrOBS = proc.Handle;//this works properly, proc is instantiated properly
SetForegroundWindow(ptrOBS); // WRONG, ptrOBS is not a window handle
Even if I trust you on ptrOBS being initialized correctly, that makes it a valid handle to a process, which is a very different thing than a valid handle to a window. Aside from the obvious nominal differences, processes can have multiple windows and only a single window can have the focus (i.e., be "in the foreground").
You will need to obtain the handle to a particular window before calling SetForegroundWindow, and given that we know a process can have multiple windows, that can be tricky. You need some reliable way of determining which window you want. Lots of people accomplish this by hard-coding the name of the window as a string, which works great until the target app is recompiled and this implementation detail changes. The only bulletproof way that I can think of is to have the user click the target window and your code to retrieve the handle of the window that is currently under the mouse pointer.
And of course all of this assumes that you've observed the restrictions on the use of SetForegroundWindow, enumerated in the "Remarks" section of the linked SDK documentation.

There is lot of trial and error with that, to get it working
Here is a bit of code I posted before, you might wanna give a try (and there is some more info attached)...
Pinvoke SetFocus to a particular control
Try setting focus first (using the mechanism mentioned) - and then using SendKeys or SendInput.
Here is some detailed code for SendInput...
How to send a string to other application including Microsoft Word

Send Message in C#

I'm creating an application that uses a main project that is connected to several different DLLs. From one DLL window I need to be able to open a window in another but the DLL's can't reference each other.
It was suggested to me to use the sendmessage function in the first DLL and have a listener in the main program that directs that message to the appropriate DLL to open it's window.
However I'm not familiar at all with the sendmessage function and am having a lot of diffculty piecing things together from information I'm finding online.
If someone could please show me the correct way (if there is any) to use the sendmessage function and maybe how a listener captures that message that would be amazing. Here is some of the code I've got so far I'm not sure if I'm heading in the right direction.
[DllImport("user32.dll")]
public static extern int FindWindow(string lpClassName, String lpWindowName);
[DllImport("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam);
public void button1_Click(object sender, EventArgs e)
{
int WindowToFind = FindWindow(null, "Form1");
}

public static extern int FindWindow(string lpClassName, String lpWindowName);
In order to find the window, you need the class name of the window. Here are some examples:
C#:
const string lpClassName = "Winamp v1.x";
IntPtr hwnd = FindWindow(lpClassName, null);
Example from a program that I made, written in VB:
hParent = FindWindow("TfrmMain", vbNullString)
In order to get the class name of a window, you'll need something called Win Spy
Once you have the handle of the window, you can send messages to it using the SendMessage(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam) function.
hWnd, here, is the result of the FindWindow function. In the above examples, this will be hwnd and hParent. It tells the SendMessage function which window to send the message to.
The second parameter, wMsg, is a constant that signifies the TYPE of message that you are sending. The message might be a keystroke (e.g. send "the enter key" or "the space bar" to a window), but it might also be a command to close the window (WM_CLOSE), a command to alter the window (hide it, show it, minimize it, alter its title, etc.), a request for information within the window (getting the title, getting text within a text box, etc.), and so on. Some common examples include the following:
Public Const WM_CHAR = &H102
Public Const WM_SETTEXT = &HC
Public Const WM_KEYDOWN = &H100
Public Const WM_KEYUP = &H101
Public Const WM_LBUTTONDOWN = &H201
Public Const WM_LBUTTONUP = &H202
Public Const WM_CLOSE = &H10
Public Const WM_COMMAND = &H111
Public Const WM_CLEAR = &H303
Public Const WM_DESTROY = &H2
Public Const WM_GETTEXT = &HD
Public Const WM_GETTEXTLENGTH = &HE
Public Const WM_LBUTTONDBLCLK = &H203
These can be found with an API viewer (or a simple text editor, such as notepad) by opening (Microsoft Visual Studio Directory)/Common/Tools/WINAPI/winapi32.txt.
The next two parameters are certain details, if they are necessary. In terms of pressing certain keys, they will specify exactly which specific key is to be pressed.
C# example, setting the text of windowHandle with WM_SETTEXT:
x = SendMessage(windowHandle, WM_SETTEXT, new IntPtr(0), m_strURL);
More examples from a program that I made, written in VB, setting a program's icon (ICON_BIG is a constant which can be found in winapi32.txt):
Call SendMessage(hParent, WM_SETICON, ICON_BIG, ByVal hIcon)
Another example from VB, pressing the space key (VK_SPACE is a constant which can be found in winapi32.txt):
Call SendMessage(button%, WM_KEYDOWN, VK_SPACE, 0)
Call SendMessage(button%, WM_KEYUP, VK_SPACE, 0)
VB sending a button click (a left button down, and then up):
Call SendMessage(button%, WM_LBUTTONDOWN, 0, 0&)
Call SendMessage(button%, WM_LBUTTONUP, 0, 0&)
No idea how to set up the listener within a .DLL, but these examples should help in understanding how to send the message.

You are almost there. (note change in the return value of FindWindow declaration). I'd recommend using RegisterWindowMessage in this case so you don't have to worry about the ins and outs of WM_USER.
[DllImport("user32.dll")]
public static extern IntPtr FindWindow(string lpClassName, String lpWindowName);
[DllImport("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll", SetLastError=true, CharSet=CharSet.Auto)]
static extern uint RegisterWindowMessage(string lpString);
public void button1_Click(object sender, EventArgs e)
{
// this would likely go in a constructor because you only need to call it
// once per process to get the id - multiple calls in the same instance
// of a windows session return the same value for a given string
uint id = RegisterWindowMessage("MyUniqueMessageIdentifier");
IntPtr WindowToFind = FindWindow(null, "Form1");
Debug.Assert(WindowToFind != IntPtr.Zero);
SendMessage(WindowToFind, id, IntPtr.Zero, IntPtr.Zero);
}
And then in your Form1 class:
class Form1 : Form
{
[DllImport("user32.dll", SetLastError=true, CharSet=CharSet.Auto)]
static extern uint RegisterWindowMessage(string lpString);
private uint _messageId = RegisterWindowMessage("MyUniqueMessageIdentifier");
protected override void WndProc(ref Message m)
{
if (m.Msg == _messageId)
{
// do stuff
}
base.WndProc(ref m);
}
}
Bear in mind I haven't compiled any of the above so some tweaking may be necessary.
Also bear in mind that other answers warning you away from SendMessage are spot on. It's not the preferred way of inter module communication nowadays and genrally speaking overriding the WndProc and using SendMessage/PostMessage implies a good understanding of how the Win32 message infrastructure works.
But if you want/need to go this route I think the above will get you going in the right direction.

You don't need to send messages.
Add an event to the one form and an event handler to the other. Then you can use a third project which references the other two to attach the event handler to the event. The two DLLs don't need to reference each other for this to work.

It doesn't sound like a good idea to use send message. I think you should try to work around the problem that the DLLs can't reference each other...

Some other options:
Common Assembly
Create another assembly that has some common interfaces that can be implemented by the assemblies.
Reflection
This has all sorts of warnings and drawbacks, but you could use reflection to instantiate / communicate with the forms. This is both slow and runtime dynamic (no static checking of this code at compile time).

Building on Mark Byers's answer.
The 3rd project could be a WCF project, hosted as a Windows Service. If all programs listened to that service, one application could call the service. The service passes the message on to all listening clients and they can perform an action if suitable.
Good WCF videos here - http://msdn.microsoft.com/en-us/netframework/dd728059

How can I get functionality similar to Spy++ in my C# app?

I'm interested in working on a plugin for Keepass, the open-source password manager. Right now, Keepass currently detects what password to copy/paste for you based off of the window title. This prevents Keepass from detecting the current password you need for apps that don't actively update their window title based on the current site (Chrome for instance).
How can I walk through another processes window elements (buttons, labels, textbox) similar to how Spy++ works? When you run Spy++ you can hover over other programs windows and get all kinds of information about various properties concerning various controls (labels, textboxes, etc). Ideally, I'd like my Keepass plugin to enhance the current window detection by walking through the active window's elements in an effort to find a matching account to copy/paste the password.
How can I walk other processes window elements and be able to retrieve label and textbox values using C#?

I've being answering similar questions like this here: How can I detect if a thread has windows handles?. Like it states, the main idea is to enumerate through process windows and their child windows using EnumWindows and EnumChildWindows API calls to get window handles and then call GetWindowText or SendDlgItemMessage with WM_GETTEXT to get window text. I've modified code to make an example which should be doing what you need (sorry it's a bit long :). It iterates through processes and their windows and dumps window text into console.
static void Main(string[] args)
{
foreach (Process procesInfo in Process.GetProcesses())
{
Console.WriteLine("process {0} {1:x}", procesInfo.ProcessName, procesInfo.Id);
foreach (ProcessThread threadInfo in procesInfo.Threads)
{
// uncomment to dump thread handles
//Console.WriteLine("\tthread {0:x}", threadInfo.Id);
IntPtr[] windows = GetWindowHandlesForThread(threadInfo.Id);
if (windows != null && windows.Length > 0)
foreach (IntPtr hWnd in windows)
Console.WriteLine("\twindow {0:x} text:{1} caption:{2}",
hWnd.ToInt32(), GetText(hWnd), GetEditText(hWnd));
}
}
Console.ReadLine();
}
private static IntPtr[] GetWindowHandlesForThread(int threadHandle)
{
_results.Clear();
EnumWindows(WindowEnum, threadHandle);
return _results.ToArray();
}
// enum windows
private delegate int EnumWindowsProc(IntPtr hwnd, int lParam);
[DllImport("user32.Dll")]
private static extern int EnumWindows(EnumWindowsProc x, int y);
[DllImport("user32")]
private static extern bool EnumChildWindows(IntPtr window, EnumWindowsProc callback, int lParam);
[DllImport("user32.dll")]
public static extern int GetWindowThreadProcessId(IntPtr handle, out int processId);
private static List<IntPtr> _results = new List<IntPtr>();
private static int WindowEnum(IntPtr hWnd, int lParam)
{
int processID = 0;
int threadID = GetWindowThreadProcessId(hWnd, out processID);
if (threadID == lParam)
{
_results.Add(hWnd);
EnumChildWindows(hWnd, WindowEnum, threadID);
}
return 1;
}
// get window text
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern int GetWindowTextLength(IntPtr hWnd);
private static string GetText(IntPtr hWnd)
{
int length = GetWindowTextLength(hWnd);
StringBuilder sb = new StringBuilder(length + 1);
GetWindowText(hWnd, sb, sb.Capacity);
return sb.ToString();
}
// get richedit text
public const int GWL_ID = -12;
public const int WM_GETTEXT = 0x000D;
[DllImport("User32.dll")]
public static extern int GetWindowLong(IntPtr hWnd, int index);
[DllImport("User32.dll")]
public static extern IntPtr SendDlgItemMessage(IntPtr hWnd, int IDDlgItem, int uMsg, int nMaxCount, StringBuilder lpString);
[DllImport("User32.dll")]
public static extern IntPtr GetParent(IntPtr hWnd);
private static StringBuilder GetEditText(IntPtr hWnd)
{
Int32 dwID = GetWindowLong(hWnd, GWL_ID);
IntPtr hWndParent = GetParent(hWnd);
StringBuilder title = new StringBuilder(128);
SendDlgItemMessage(hWndParent, dwID, WM_GETTEXT, 128, title);
return title;
}
hope this helps, regards

Have a look at this article here which contains information about the Managed Spy and why the author wrote the tool.

You can use EnumWindows to find every top-level Chrome window and then call EnumChildWindows recursively (see Jeroen Wiert Pluimers' comment) to get every child of the main window. Alternatively, once you have the main Chrome window, you can use GetWindow to manually navigate the tree since you probably know what you're looking for (3rd child's children collection or something similar).
Once you find your window, you can use SendMessage with a WM_GETTEXT parameter to read the window's label.

You can use HWndSpy. Source code is here.

For the functionality of pointing to a window. You need to SetCapture() so that you get mouse messages that are outside of your window. Then use WindowFromPoint() to convert a mouse position to a Window. You will need to convert the moust position from client coordinates to window coordinates first.
If you try an call SetCapture() anywhere but on a mouse click message, you will probably be ignored. This is the reason that Spy++ makes you click on an Icon and drag and drop it on the window you want to point to.